Certain combinations of explosion-welded material, such as stainless steel/carbon steel, nickel alloys/carbon steel, titanium/carbon steel, and so on are rolled after being joined together, so as to give a larger format of reduced thickness.
This procedure is known and has been used for many years.
Normally the explosion-welded plates are rolled one by one. However, in some cases, if a thinner final product is required or if unfavourable flow in the rolling process is to be reduced, a method known as package rolling is used, i.e. two plated sheets (compound sheets) are placed together with the plating sides facing each other, and the package is welded around the edges. The complete package is then welded.
To enable this package manufacture, the area of the plating material must be less than that of the base material, so that a free edge of base material is left around the plating material.
However, when explosion welding material of the thicknesses normal in this connection (10 mm-30 mm plating thickness), this known technique requires the entire surface of the base material to be plated and the edge of the plating material must therefore be removed after joining and before package-welding, by means of planing, for instance.